SAM MEDNICK IT took Aicha Sylla three attempts to get a prescription for hormones in Burkina Faso so she could start to transition gender. In the end, one doctor agreed - if she had sex with him first. "I didn't have any choice ... The other doctors didn't even listen to me; they refused," Sylla, 22, told the Thomson Reuters Foundation, visibly upset, as she sat in a restaurant in the capital, Ouagadougou. Despite the health risks, she has been self-medicating ever since using the same prescription, a practice that trans rights advocates say is widespread among transgender people in…